In an image forming apparatus using an electro-photographic method, such as a copying machine, a printer, a facsimile, and a compound-machine having several of these functions, since moisture in the recording sheet is decreased during the heat fixing process, problems occur due to the sheet being curled or wavy. One way to counter these problems, is moisturizing the sheet after the fixing process.
Unexamined Japanese Patent Application Publication No. 2006-8282 discloses a sheet moisturizing apparatus including paired moisturizing rollers to nip and convey a sheet, a water supplying device which supplies water on the surface of at least one of the paired moisturizing rollers, and a restricting section which restricts water amount to be supplied to the surface of at least one of the paired moisturizing rollers.
U.S. Pat. No. 5,987,301 discloses a moisture control system of a recording sheet, in which the sheet, ejected from a fixing device, is horizontally conveyed, and is nipped by a paired moisturizing rollers to be ejected. The sheet moisturizing device in this system includes the paired moisturizing rollers, a compromising roller and a water supplying roller, each arranged either above and below the sheet conveyance path.
The sheet moisturizing device of each Patent Document has a single water tank in which the water supplying roller is partially submerged.
A wavy sheet, ejected from a heat fixing device, is moisturized by the sheet moisturizing device, whereby the wavy sheet is flattened. However, it is very difficult to completely seal the water supplying roller and the water tank in which the water supplying roller is partially submerged. Further, when the sheet remedying apparatus is displaced, or when the sheet moisturizing device is installed in or withdrawn from the sheet remedying apparatus, water stored in the tank is agitated and flows out through gaps between the water tank and the water supplying roller, whereby the sheet moisturizing device becomes wet, which results in malfunctioning of sheet conveyance, such as sheet jamming in various places of the sheet conveyance path.